Microarrays for biomolecular assays are typically formed on glass slides. The arrays may be formed of DNA (or other polynucleotide forms such as cDNA or RNA). The arrayed DNA may be synthesized on the glass slide, or robotically dispensed onto the slide into an array format.
Glass slides have been the substrate of choice for microarrays because glass has desirable structural, optical and chemical properties. For example, glass has sufficient rigidity and hardness for maintaining uniform flatness and withstanding unwanted bending. Moreover, glass exhibits very low fluorescent background in the most relevant excitation and emission wavelength ranges for biomolecular assays. Finally, glass is chemically resistant to the reagents generally used in biomolecular assays. A typical glass slide is shown in FIG. 1.
However, glass slides have several significant drawbacks. Glass is fragile and breakable when subjected to undesired impacts, such as from dispensing equipment. Additionally, glass slides do not allow for high throughput applications because a glass slide accommodates only a single assay site. This is because there are no physical barriers on the slide to prevent cross-contamination of multiple assay sites. Accordingly, in many cases, most of the surface of a glass slide goes unused, especially in low and medium density arrays.
Therefore there is a need for a microarray slide which overcomes the aforementioned problems with glass slides and which allows for high throughput by accommodating multiple assay sites on a single slide.